Sin 3x=3sinx-4sin³x solve the identity step by step ​

Problem melissa is her dad build a walkway in their backyard. the walkway will be 54 feet long and 1.5 feet wide. the local hardware store sells tiles which are 1.5 by 1.5 feet and come in boxes of 12. how many boxes of tiles do they need?

Can someone me out here number 4 plz

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x